A pouncing lion can make 5 attacks without grappling
The extraordinary ability pounce says, "When a creature with this special attack makes a charge, it can follow with a full attack—including rake attacks if the creature also has the rake ability" (Monster Manual 313). There're few reasons for the pounce ability to mention rake attacks if it weren't making an exception as to how rake attacks work normally.
With this in mind, a creature that possesses the extraordinary ability rake—like a lion (274–5)—can charge, pounce, and use its rake attacks without obeying the normal rules for the rake ability, reproduced below:
A creature with this special attack gains extra natural attacks when it grapples its foe. Normally, a monster can attack with only one of its natural weapons while grappling, but a monster with the rake ability usually gains two additional claw attacks that it can use only against a grappled foe. Rake attacks are not subject to the usual –4 penalty for attacking with a natural weapon in a grapple. (313–14)
Were the pounce ability not to make an exception for the rake ability, to bring its rake attacks to bear against a foe, a lion, for example, on a charge would make its two claw attacks then its bite attack then, if that's successful, make its grapple attempt due to its extraordinary ability improved grab (310) then, if that's successful, take the grapple option Attack Your Opponent (Player's Handbook 156) for its rake attacks against the grappled foe, and the lion—were its foe not dead—would end its turn in a grapple. (This writer is familiar with the one-handed grapple rules present in the description of the improved grab ability, but this writer's keeping things simple.)
Note that a lion can still do that whole claw-claw-bite-grab-rake-rake routine above if it wants to—and it will in many situations—, but the exception made by the pounce ability for the lion's rake ability means that a lion isn't forced to if the lion wants to bring to bear all of its natural weapons yet not begin a grapple for whatever reason—like the lion wants to be able to make a quick getaway or the lion's outnumbered.
For example, a lion can charge a one commoner in a group of commoners in tight formation and—spectacularly!—because of the pounce ability leave five of those commoners dying, the lion having spent its first claw attack on the target of its charge, its second claw attack on another adjacent commoner, its bite on a third, one of its rake attacks on a fourth, and its other rake attack on a fifth.